翻译下
This chapter deals with one-dimensional calculation procedures and design meth-
ods for impellers, volute casings, diffusers and inlet casings. For developing these
components, the main dimensions and blade angles are calculated in a first step.
Subsequently, the hydraulic contours are designed based on certain rules and
methods. Many pump manufacturers employ computer programs for this work,
and the drawings are generated on 2D-CAD systems. However, these methods are
also increasingly replaced by 3D-CAD systems with which fully three-dimensio-
nal geometry models of a component can be created, Fig. 2.2A and Fig. 7.40. The
complex hydraulic channels can be evaluated better with such models than with
the conventional two-dimensional representations in various sections and views.
Even more importantly, 3D-CAD systems provide the capability to directly manu-
facture the hydraulic components (or the casting patterns) by NC milling, stereo li-
thography or other fast-prototyping processes, [7.1]. The advantages of such proc-
esses are evident in terms of geometrical accuracy and lead times (not in the least
also for model tests with milled or stereo-lithographed components). Since manual
designs on the drawing board are rather the exception, the subsequent discussion
of the design methods emphasizes the fundamental aspects of the design processes
rather than a very detailed description of geometrical operations.
This chapter deals with one-dimensional calculation procedures and design meth-
ods for impellers, volute casings, diffusers and inlet casings. For developing these
components, the main dimensions and blade angles are calculated in a first step.
Subsequently, the hydraulic contours are designed based on certain rules and
methods. Many pump manufacturers employ computer programs for this work,
and the drawings are generated on 2D-CAD systems. However, these methods are
also increasingly replaced by 3D-CAD systems with which fully three-dimensio-
nal geometry models of a component can be created, Fig. 2.2A and Fig. 7.40. The
complex hydraulic channels can be evaluated better with such models than with
the conventional two-dimensional representations in various sections and views.
Even more importantly, 3D-CAD systems provide the capability to directly manu-
facture the hydraulic components (or the casting patterns) by NC milling, stereo li-
thography or other fast-prototyping processes, [7.1]. The advantages of such proc-
esses are evident in terms of geometrical accuracy and lead times (not in the least
also for model tests with milled or stereo-lithographed components). Since manual
designs on the drawing board are rather the exception, the subsequent discussion
of the design methods emphasizes the fundamental aspects of the design processes
rather than a very detailed description of geometrical operations.
